Sound-record for talking-machines.



N0 MODEL.

` PATENTE). sEptlLzz, 1903.' .R11-.Jonsonv A l SAO'UND RECORD FOR' TAL'KING'MACHINES.

APPLIOATION FILED'AUG. 1900.

jig. 7.

m: Nonms Patins cu, mmc-urna. wmmoon, u r.,

f UNITED-. N 'S :ATE-sl Patented'september 22, 2.1903. .I

PATENT OFFICE. f

ELDRIDGE R. JOHNSON, OE'PIIILADELPI'IIA, PENNSYLVANIA, AssIcNoR To VICTOR TALKING MACHINE COMPANY, A CORPORATION or NEW JERSEY.

. VSOUND-'RECORDFOR TALKING-MACHINES.

SPECIFICATION forming part of Letters Patent N 0. 739,421, dated September 22, 1903.

Application iiled August 8, 1900. Serial No. 26.275. (No model.)

To all VwhomA t `may concern:

Be it known thatl, ELDRIDGE IR. v JOHNSON,

acitizen of the United States, anda residentV of the city of Philadelphia, State of Pennsyl- Vania, have invented certain new and useful Improvements in SoundRecordS for Talking- Machines, of which'the following isa full, clear, and exactdescription,reference being had to the accompanying drawings, lforming part of this specification.

This invention relates to an improved soundrecord, and particularly to flat records,

such as are used on gramophones and other sound-reprod ucin'g machines.

The Object of thisinvention 1s to produce a' record having a serrated or vribbed under surface in order that it may bear against the turn-table or record-support of the motor with increased frictional Contact and maintain its position on said record-support durthrough an aperture -formed in the Yc enter ofl the record andin providing a ilanged nut adapted to it on thesaid screw-threaded boss vand bear against ythe record, and thus hold it in position during the operation of the ma# chine. My invention is designed for the purpose of doing away with the flanged nut and constructing the record so that its own frictional contact will hold it to the record-Support or turn-table and prevent it from turning except when the turn-table revolves.

In-the accompanying drawings, in which similar letters of reference are used to indicate similar parts, Figure'l is a bottom plan View of the soundrecord constructed in acv cordancewith my invention. Fig. 2 is a sectional view showingthe record mounted upon a turn-table. Fig. 3 is adetail section on the line 3 3 of Fig.r1. v y l.

In machines'of the gramophone type the record is supported upon a circular disk, as A, which is mounted on a spindle B, the said spindle being suitably connected to ,and

face of theturn-table is provided a layer of Ibaize or felt a, upon which the flatrcircular record rests.

In carrying out my invention ,I form a circular record-disk 0having thek sound-waves recorded thereon in the usual manner on the drivenbya spring-motor. On the upper surupper surface of said disk. Theunder sur- .l

face of the disk is provided with a smooth circular center, as D, having a central aperture YE, passingl therethrough, adapted when the record is in position to receive the boss a,

which projects through the center ofthe turn l table A. Extending radially from the smooth circular,portionY B are a number'of Sharppointed ridges, asc, extending to the circum- `,ference of the said record-disk. These ribs l are located quite `close together, asillustrated in the drawings, and the lower edges of the same are adapted to bear against the baize or other covering provided on the upper Surface of the turn-table A, andthe weight of the record is `sufficient to cause the said ribs to become slightly embeddedin the cloth, felt,

yor other material, and thereby hold the said record in olose'frictionalcontact with the'turntable with a sufficient degree offirmness to Aprevent ofits being moved independently of the turntable during the engagement of the stylusqooint'with the record-groove in the operation of the machine. Owing to the radial arrangement of the ridges c the spaces be tween them and above the cloth will contain air, which Will be carried around with the table and record when the same is rotated.

The centrifugal force produced by this rotation will tend to expel the air at the periphery of the record and so create a'partial vacuulnybetween the record and the turn-table or the cloth thereon This partial vacuum will greatly increase the frictional Contact of the record with the table and so produce very I claim, and desire to secure by Letters Patent, is

A sound-record for talking-machines comprising a hat disk having sound-Waves re- 5 corded on one surface thereof, a. central aperture provided iu said disk for centering the same upon the reeordsupport, a series of sharpened radial ribs provided on the under surface of said disk, a record-support, and a textile covering for said support adapted to 1o Contact with the ribs ou the record, substantally as described.

In Witness whereof I have hereunto set my hand this 3d day of August, A. D. 1900.

ELDRIDGE R. JOHNSON. .Vitnesses:

JN0. T. ORoss, LEWIS H. VAN DUSEN. 

